In electronic control systems, it is frequently desirable that its components be constructed in a modular manner to permit the replacement of a system component without disturbing other components. This approach is desirable for reasons related to possible malfunction and resultant service requirements or to changes which are required to be made in the system configuration. Yet another reason for modular construction is that portions of the control modules may be made identical one to the other or nearly so in order that certain manufacturing economies may be realized. Still another reason for such construction is that it permits configuration of a wide variety of system architectures using a plurality of relatively standardized modules.
One approach to the construction of a modular system is shown and described in West German Offenlegungsschrift No. 2 205 086. The modules shown therein are formed of substantially identical housings, each having screw-type terminals for the connection of incoming and outgoing electrical wires. Electrical power is supplied to the modules through a pin type cross connecting system whereby the modules are required to be plugged or assembled together prior to gang mounting of the modules upon a support rail.
Yet another approach to modular design is shown in U.S. Pat. No. 2,910,672 wherein intermodule connection is by a plurality of pins projecting from one side of a module, the pins being received into appropriate sockets formed in the opposite side of the adjacent module. System assembly is by sequentially stacking the modules after which the modules are maintained in an electrically-connective relationship by a throughbolt. Other ways of using a modular approach in system construction are shown and described in U.S. Pat. Nos. 3,403,300 and 3,373,319.
While these approaches to modular system construction have heretofore been satisfactory, they tend to be characterized by certain disadvantages. In particular, they have failed to appreciate the manner in which modules may be constructed to permit swingable module mounting and removal whereby any module may be removed and replaced without disturbing adjacent modules. Additionally, they have failed to appreciate the manner by which a module may be constructed using a plurality of bus conductors which are constructed and arranged to engage the bus conductors of adjacent modules. The bus conductors may thereby define a system power bus for providing electrical power to the modules and may also define a system communication bus for providing a module communication channel. An electronic control module which is adapted for swingable mounting to a rail member, which includes a plurality of bus conductors for providing system electrical power and communication links, which is adapted to be individually removable and replaceable without disturbing adjacent modules and which includes a frame for receiving an electrical circuit board having any one of a variety of circuit configurations would be a distinct advance in the art.